KR940000876A

KR940000876A - High Sensitivity Magnetic Sensor

Info

Publication number: KR940000876A
Application number: KR1019920009639A
Authority: KR
Inventors: 남태철
Original assignee: 남태철
Priority date: 1992-06-03
Filing date: 1992-06-03
Publication date: 1994-01-10

Abstract

본 발명은 자장을 검출하는 자기센서로서. 자장을 감지하는 홀소자와. 홀소자의 홀신호를 변조하기 위해 홀소자를 주파수 fo의 전원으로 구동하는 구동전원, 상기 홀소자의 출력단에 발생하는 오프셋전압 (Offset Voltage)을 제거하기 위해 홀소자의 출력단에서 발생하는 오프셋전압과 구동전원의 양단에서 발생하는 오프셋전압과 구동전원의 양단에서 발생하는 전압을 무(無)자계에서 같은 진폭의 크기 가 되도록 각각 증폭하는 제 1, 2증폭수단, 상기 제1, 2중폭수단 각각의 출력중 일정한 주파수 대역의 신호만을 통과시키고 신호의 일그러짐을 방지하는 저역통과 여파기, 상기 대역통과여파기의 두 출력신호의 차신호를 구하는 차동증폭수단 및 상기 오프셋전압이 제거된 차신호를 입력하여 신호의 증폭과정등에서 발생한 잡음가 캐리어 주파수(Carrier Frequency)를 제거하고 원래의 자장과 비례하는 홀신호를 출력하는 복조수단으로 구성되어 홀소자와 증폭수단에서 발생하는 오프셋 및 잡음을 제거하여 극히 미량의 자장을 고감도로 감지할수 있는 고감도 자기센서이다.The present invention is a magnetic sensor for detecting a magnetic field. Hall element to detect the magnetic field. A driving power supply for driving the Hall element with a power of a frequency fo to modulate the Hall signal of the Hall element, and an offset voltage generated at the output end of the Hall element and both ends of the driving power to remove the offset voltage generated at the output end of the Hall element. Constant frequency among the outputs of the first and second amplifying means and the first and second amplifying means, respectively, for amplifying the offset voltage generated at and the voltage generated at both ends of the driving power to have the same amplitude in the magnetic field. A low pass filter for passing only a signal in a band and preventing distortion of the signal, a differential amplifying means for obtaining a difference signal between two output signals of the band pass filter, and a difference signal from which the offset voltage has been removed is input. Demodulation means for outputting Hall signal in which noise removes carrier frequency and is proportional to original magnetic field It consists of a high-sensitivity magnetic sensor that can detect a very small amount of a magnetic field to remove the offsets and noise from the hall element and the amplifying means with a high sensitivity.

Description

High Sensitivity Magnetic Sensor

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is an open matter, no full text was included.

제1도는 본발명 고감도자기센서의 상세한 회로구성도,1 is a detailed circuit diagram of the high-sensitivity magnetic sensor of the present invention,

제2도 (A), (B)는 본 발명에 따른 각부 신호의 주파수 스펙트럼을 나타낸 것으로, (A)는 홀소자(1) 출력신호의 주파수 스펙트럼, (B)는 구동전원(2)의 단자(S, T)양단에 나타나는 신호는 주파수 스펙트럼,2 (A) and (B) show the frequency spectrum of each part signal according to the present invention, (A) is the frequency spectrum of the output signal of the Hall element (1), (B) is the terminal of the driving power source (2) The signal that appears across (S, T) is the frequency spectrum,

제3도는 (A), (B)는 본발명에 따른 각부신호의 주파수 스펙트럼을 나타낸 것으로, (A)는 제1증폭수단(3)에서 출력되는 신호의 주파수 스펙트럼, (B)는 제2증폭수단(4)에서 출력되는 신호의 주파수 스펙트럼,Figure 3 shows the frequency spectrum of each part signal according to the present invention (A), (B), (A) is the frequency spectrum of the signal output from the first amplifying means (3), (B) is the second amplification The frequency spectrum of the signal output from the means 4,

제4도는 차동증폭기(7)에서 출력되는 신호의 주파수 스펙트럼을 나타낸 도면.4 shows the frequency spectrum of the signal output from the differential amplifier 7;

Claims

Hall element 1 for detecting the magnetic field, driving power source 2 for driving Hall element 1 to the power of main fruit fo to modulate the Hall signal of Hall element 1, In order to remove the offset voltage generated at the output terminals X and Y, the offset voltage generated at the output terminals X and Y of the hall element 1 and at both ends S and T of the driving power supply 2 are eliminated. Constant frequency bands among the outputs of the first and second amplifying means 3 and 4 and the first and second amplifying means 3 and 4 respectively amplifying the generated voltages to have the same amplitude in the magnetic field. A low pass filter (5, 6) for passing only a signal of and preventing distortion of the signal, a differential amplification means (7) for obtaining a difference signal between two output signals of the band pass filter (5, 6), and the offset voltage are removed. Input the difference signal to remove the noise and carrier frequency generated during the signal amplification process, etc. High-sensitivity magnetic sensor, characterized in that it is composed of a demodulation means (8) for outputting a Hall signal to detect the extremely small amount of magnetic field with high sensitivity by removing the offset and noise generated from the Hall element and the amplification means

2. The high sensitivity magnetic sensor as claimed in claim 1, wherein the demodulation means (8) consists of a multiplexer (10) and a low pass filter (11).

The high sensitivity magnetic sensor as claimed in claim 1, wherein the demodulation means (8) is a detection circuit composed of a distillation means (12) and a low pass filter (11).

※ Note: The disclosure is based on the initial application.